Method of controlling fungus infections with 3-halogeno-4-nitro-6-lower alkylpyridazine-1-oxide



United States Patent METHOD OF CONTROLLING FUNGUS ENFEC- TIONS WITH 3-HALOGENO-4-NI'I'RQ-E LOWER ALKYLPYRDAZME-l-OXIDE Hideo Kano, Kurnikyo-ku, Kyoto-511i, and Masaru'flgata, Higashinada-ku, Kohe-shi, Japan, assignors to Shionogi & Co., Ltd, Osaka, Japan No Drawing. Griginal application Sept. 6, ULSer. No. 221,885. Divided and this application June -19, 1963, Ser. No. 299,132

Claims priority, appiicafion Japan Feb. 26, 1962 3 Claims. (Cl. 167-58) The present invention relates to anti-fungal pyridazine derivatives. More particularly, it relates to the 3 h2il0- geno-4-nitro-6-alkylypyiidazine-l-oxides corresponding to the following general formula:

wherein R and R have each the same significance as designated above, with a nitrating agent such as nitric acid, a mixture of nitric acid andsulfuric acid, a combination of an inorganic nitrate (e.g., sodium nitrate, vpotassium nitrate) with sulfuric acid and nitrogen dioxide, if

necessary, in a suitable medium such as sulfuric acid, glacial acetic acid and nitrobenzene to give the compound I. V v

The starting compound 11 can be prepared according to the following scheme:

[Overend et al.: J. Chem. Soc., 239 (1947)] 7 RK QK lCaHsC O 0011 3,150,559 Patented Dec. 8, 1964 R- X 'R I 1 '(X=C1orBr) 5* 15 wherein R and *R have each the same significance as designated above. 7

Of the "said nitrati'ng agents, the use of a mixture of nitric acid andsulfuric acid is the most preferable, and a typical procedure is "illustratively set forth as follows: The compound is added'to a "mixture of turning nitric'aciii andconcjs'ulfuricadd while cooling, and then hated on a water hath for several "hours. The reaction mixture is pouredi'nto ice water and shaken 'with awaterimmiscible solvent such as dichlorom'ethane, chloroform and carbon tetrachloride, fReinoving the solvent fromthe'solventlayen'there is obtainedjthe'compound I.

The 3 halogeno 4-nitr0 6 alkylpyridazine-l-oxides corresponding to Formula I show broad antimicrobial spectra against a variety of microor anisms, especially fungi. Thus, the in vitro sensitivity of bacteriaa'ndtiingi to the compound I was iietermined by an agar streak dilution "method. Serial two fold dilutions of the compound I were prepared in appropriate media and the surface of the agar was streaked with suitable dilutions of young cultures. The minimum inhibitory concentrations were found for each'organism as the lowest concentration'of the compound I at which there was no visible growth of bacteria and fugi. For comparison, tests were also run using "the heretofore known anti-fungal agents,

'i;e., griseofulvin and ttichomycin.

TABLE I Antibacterial Activity 0) 3-Hzil0gen0-4-Nilr0 6 Alkyl- .pyridazine-l-Oxides (as Determined by Agar-Streak Method on Peptone-Meat Extract Agar, Readings After 48 Hoursat 37 C.) r

50 inhibitory concentration 7 (meg/ml.) Test organisms -3-chloroo 3-b'romo- 3-iod'o-' G-methyl fi methyl S-methyl Shigella dysenteriae 5. 0 5. 0 5. O Shigella paradysenteriaa 20.0 20. O 10. (1 Salmonella typlmsa 20. 0 20. O 20.0 Salmonella pgratyphi l0. 0 l0. 0 5. 0 Escherichia coli 50. 0 20. 0 20, 0 Pseudomo'nas aerugz'nosa. 50. 0 50. 0 50. 0 Klebsiella pneumoniae 20.0 a 20. 0 10. 0 6D Bacilluasubtilis, PCI-219 5. 0 '5. 0 lfO Bacillus anthracis. .2. 0 5. 0 2. 0 Staphylococcus aureus 209 P 20. 0 20. 0 5,0 Careimz Zutea; 20:0 20. 0 10. 0

due to Trichophyton.

TABLE II on 2 Glucose-Sabow'aztds Agar) Minimum inhibitory concentration (meg/m1.)

3-Halogeno4-nitro-6- Test organisms alkylpyridazinel-oxide Grisco- Tricliofulvin mycin 3-chloro- 3-bromo- 3-iodo- 6-methyl G-methyl G-methyl Trichophyton pedis 1. 6 1. 6 0.8 6.3 25.0 Trichophyton purpztreztm 0.8 3. 1 0.8 3. 1 50.0 Trichoplzyton rubrum 0. S 1. 6 0.8 1. 6 12.5 Trichophyton gypseum 0.8 1. 6 0.8 6.3 100.0 Trichophyton mentagrophytes. 0. 8 1. 6 0.8 6. 3 50. Triclzophyton interdzgilalc 3.1 3. 1 3. l 12. 5 100.0 Candida albicans 100.0 100. 0. 100.0 100. 0 1. 6 Candida tropicalis. 100.0 100.0 100. 0 100. 0 1.6 Aspergillus glaucus 1.6 1. 0 1.0 100. 0 0. 8 Aspergzllus oryzae 6. 3 6.3 6. 3 100. O 12.5 ASPETfll ll'ZLS niger 50.0 50. 0 50.0 100. 0 3.1 Penicillium digitatum. 3. 1 3. 1 1. 6 100. 0 0. 8 Rhodotornla sp 50. 0 50.0 100.0 100. 0 1. 6 Saccharomyces cereuis e 25.0 12. 5 25.0 100. 0 0. 8 Torula sp 25.0 25. 0 50. 0 100. 0 0. 8

readings after 3 days at 28 0.; Candida and Yeast, readings after 2 days at 28.

As listed in Tables I and II, the 3-halogeno-4-nitro-6- alkylpyridazine-loxides corresponding to Formula I are active against bacteria and fungi. Although their antibacterial activity is medial, their antifungal activity is stronger and/ or broader than that of griseofulvin and trichomycin. Particularly, their high activity against various species of Trichophytonis noteworthy. Determination of fungicidal activity was accomplished by placing, for instance, 3-chloro-4 nitr0-6-methylpyridazine-l-oxide in contact with cells of Trichophyton interdigitale in sterile saline solution. After the periods of contact, the cells were Washed thrice with sterile saline solution and subcultures were made at intervals by an inoculating loop on glucose- Sabourauds agar for growth observations.

TABLE III Fzmgicidal Action of 3-Chl0ro-4-Nitro-6-Methylpyridazine-l-Oxia'e Against Cells of Trichophyton interdigitale Suspended in Saline Solution Growth of Trichophyton interdigitale 1 1 subcultures incubated at 37 0. Final readings made after 7 days. 2 Sterile saline was used as the control.

No growth.

:b, and Slight to full growth.

As listed inTable III, the compound I is a remarkable fungicidal agent against Trichophyton. Accordingly, the

3-halogeno-4-nitro-6-alkylpyridazine-l-oxides corresponding to Formula I are useful as fungistatic and fungicidal agents, especially in the treatment of superficial mycoses For instance, they can be used as externally applicable medicaments for controlling the infections caused by pathogenic .Trichophyton such as trichophytia pompholyciformis, trichophytia eczematosa and trichophytia maculovesiculosa in the form of creams, ointments, solutions, suspensions, powders and the like.

The present application is a division of copending application, Serial No. 221,885, filed September 6,1962.

Practical and presently preferred embodiments of the present invention are illustrated by the following examples. The abbreviations used in these examples are intended to have the following meanings: ml., millilitre(s); mg, milligram(s); and C., degrees centigrade. Other abbreviations have each a conventional meaning.

EXAMPLE 1 To a mixture of cone. sulfuric acid (2 ml.) and fuming nitric acid (0.5 ml.), there is added 3-chloro-6-methylpyridazine-l-oxide (500 mg.) while ice-cooling, and the resultant mixture is heated for 6 hours on a water bath. Then, the reaction mixture is poured into ice-water and shaken with chloroform. Removing the solvent from the chloroform layer, the resulting substance is crystallized from benzene to give 3-chloro-4-nitro-6-methylpyridazinel-oxide (210 mg.) as needles melting at 103 to 103.5 C.

Analysis.Calcd. for C H O N Cl: C, 31.66; H, 2.12; N, 22.17. Found: C, 31.49; H, 2.30; N, 22.05.

The starting material of this example, 3-chlor0-6-methylpyridazine-l-oxide, can be produced by reacting S-chloro- 6-methylpyridazine [Overend et al.: J. Chem. Soc., 239 (1947)] with perbenzoic acid in chloroform at 30 C.

, EXAMPLE 2 To a mixture of cone. sulfuric acid (2 ml.) and fuming nitric acid (1 ml.), there is added 3-bromo-6-methylpyridazine-l-oxide (400 mg.) while ice-cooling, and the resultant mixture is heated for 3 hours on a water bath. Then, the reaction mixture is poured into ice-water and shaken with chloroform. Removing the solvent from the chloroform layer, the resulting substance is crystallized from ethanol to give 3-bromo-4-nitro-6-methylpyridazinel-oxide mg.) as prisms melting at 123 to 124 C.

Analysis.-Calcd. for C H O N Br: C, 25.64.; H, 1.71; N, 17.95. Found: C, 25.99; H, 1.93; N, 17.49.

The starting material of this example, 3-bromo-6- methylpyridazine-l-oxide, can be produced by reacting 3-hydroxy-6-methylpyridazine [Overend et al.: J. Chem. Soc., 239 (1947)] with phosphorus oxybromide at 60 C. and treating the resulting 3-bromo-6-methylpyridazine with perbenzoicacid in chloroform at 25 C.

EXAMPLE 3 To a mixture of cone. sulfuric acid (2 ml.) and fuming nitric acid (0.5 ml.) there is added 3-iodo-6-methylpyridazine-l-oxide (500 mg.) while ice-cooling, and the resultant mixture is heated for 2.5 hours on a water bath. Then, the reaction mixture is poured into ice-water and shaken with chloroform. Removing the solvent from the chloroform layer, the resulting substance is crystallized 25 kilograms of a topical cream for treating fungous infections of the skin or scalp are prepared from the following types and amounts of materials:

Grams Stearic acid, N.F 5000 Isopropyl myristate 500 3-chloro-4-nitro-6-methylpyridazine-l-oxide 62.5 Methylparaben, U.S.P. 25 Triethanolamine, U.S.P. 500 Propylene glycol, U.S.P 2500 Perfume, q.s.

Deionized water, q.s. to 25,000 grams.

The stearic acid is melted and the isopropyl myristate mixed therein. The finely powdered 3-chloro-4-nitro-6- methylpyridazine-l-oxide is suspended in the mixture. The methylparaben is dissolved in part of the water at about 70 C., and the triethanolamine and propylene glycol are added to the aqueous solution. With constant stirring the aqueous solution is combined with the 3-chloro-4- nitro-6-methylpyridazine-l-oxide-stearic acid isopropyl myristate mixture. The combination is stirred until the temperature reaches about 40 C. The perfume is added and any water loss replaced. Stirring is continued until congealing occurs. The cream is assayed for potency and filled into g. tubes. The preparation is suitable for use in the treatment of moderately severe tinea barbae of the face or neck by direct application to infected areas of the skin twice a day.

EXAMPLE 5 A tincture containing in each 1 ml. 20 mg. of 3-chloro- 4-nitro-6 methylpyridazine-l-oxide is prepared from the following types and amounts of ingredients:

Grams 3-chloro-4-nitro-6-methylpyridazine-l-oxide 20 Methyl salicylate 2O 22% aqueous ethanol, q.s. to 1000 millilitres.

Two applications of the tincture per day to feet infected with moderately severe athletes foot would be suitable course of treatment until symptoms subside.

EXAMPLE 6 A topical dusting powder suitable for the treatment of fungous infections on the foot or on other parts of the body is. prepared from the following types and amounts of ingredients:

Grams 3-chloro-4-nitro-6-methylpyridazine-l-oxide 10 Fine powder (200 mesh). Zinc stearate 350 Bentonite 640 Two applications of the powder per day to feet infected with moderately severe athletes foot would be suitable course of treatment until symptoms subside.

What is claimed is:

1. A method of controlling the infections caused by pathogenic Trichophy-ton, which comprises the dosage administration externally of a pharmaceutical preparation comprising 3-halogeno-4-nitro-6-lower alkylpyridazine-loxide as an active ingredient.

2. A method of controlling the infections caused by pathogenic Trichophyton, which comprises the dosage administration externally of a pharmaceutical preparation comprising 3-chloro-4-nitro-6-rnethylpyridazine-l-oxide as an active ingredient.

3. A method of controlling the infections caused by pathogenic Trichophyton, which comprises the dosage administration externally of a pharmaceutical preparation comprising 3-i0do-4-nitro 6-methylpyridazine-l-oxide as an active ingredient.

No references cited. 

1. A METHOD OF CONTROLLING THE INFECTIONS CAUSED BY PATHOGENIC TRICHOPHYTON, WHICH COMPRISES THE DOSAGE ADMINISTRATION EXTERNALLY OF A PHARMACEUTICAL PREPARATION COMPRISING 3-HALOGENO-4-NITRO-6-LOWER ALKYLPYRIDAZINE-1OXIDE AS AN ACTIVE INGREIDIENT. 